Quantitation of Amino Acids in Dried Blood Spots by iTRAQ~(~R) Reagent Derivatization Reaction and LC/MS/MS Analysis

摘要

Dried blood spots (DBS) are the standardized sampling method for the screening of inborn errors of amino acid metabolism. Recent publications report quantitation of amino acids (AA's) in physiological fluids such as plasma, urine and cerebrospinal fluid (CSF) by LC/MS/MS using iTRAQ~(~R) Reagents. This method allows measurement of individual isobaric AA's and provides quantitative information on almost twice the number of AA's than the conventional screening method. However, this method has not been applied to dried blood spots. This study investigates an extraction protocol to quantify 45 physiological AA's from DBS using the iTRAQ~(~R) Reagent labeling method.